The present invention relates to an optical device and in particular to an optical device applied to a projector, an optical switch, a bar code or a copier.
The projector, optical switch, bar code and copier are equipped with an optical device shown in FIG. 1.
FIG. 1 shows a related art optical device.
Referring to FIG. 1, an optical device 100 comprises a light source 101, a reflector 102, a mirror element housing body 103, a mirror element 104, and a projection lens 105.
The light source 101 is provided in a position apart from the mirror element 104, element housing body 103, and projection lens 105. The light source 101 is used to emit light toward the mirror element 104. The light source 101 may be a halogen lamp. The reflector 102 is arranged so as to surround the light source 101. The reflector 102 is used to reflect the light emitted from the light source 101 toward the mirror element 104.
The mirror element housing body 103 includes a substrate 106 and a cover 107. The substrate 106 includes a wiring pattern (not shown) electrically connected to the mirror element 104. The cover 107 is arranged so as to surround the mirror element 104 arranged on the substrate 106. The cover 107 is formed by a translucent material.
The mirror element 104 is electrically connected to a wiring pattern (not shown) provided on the substrate 106.
The mirror element 104 includes a plurality of mirrors 109 arranged in a lattice shape. The plurality of mirrors 109 are provided on the upper face of the mirror element 104. Each of the plurality of mirrors 109 is designed to change its angle independently of the other mirrors 109. Each of the plurality of mirrors 109 changes its angle to switch between the ON and OFF states. The ON state refers to a state where light from the light source 101 is reflected onto the projection lens 105. The OFF state refers to a state where light from the light source 101 is not reflected onto the projection lens 105.
The projection lens 105 is arranged apart from the light source 101, reflector 102, mirror element housing body 103 and mirror element 104. The projection lens 105 is used to expansively project the light reflected by the mirrors 109 (for example, refer to Patent Reference 1).
To display a color image, a color filter (not shown) is separately provided between the light source 101 and the mirror element 104.
[Patent Reference 1] JP-A-2004-117931
With the related art optical device 100, the light source 101 and the reflector 102 are arranged apart from the mirror element housing body 103 and the mirror element 104 as independent components. This results in an increase in the size of the optical device 100, thus making it difficult to downsize the optical device 100.